Saturday's byelection for the New South Wales state seat of Orange might not loom terribly large among the global electoral convulsions that have characterised 2016, but it certainly marks a significant moment in the increasingly troubled life of Mike Baird's government, and it is not without resonance of the anti-establishment backlash unfolding internationally.

Centred around the rural centres of Orange, Parkes and Forbes about 250 kilometres west of Sydney, the seat is classic Nationals heartland, and has been held by the party without interruption since 1947.